Returns a Method
of superclass which would be called when super is used or nil if there is no method on superclass.
Returns a Method
of superclass which would be called when super is used or nil if there is no method on superclass.
Closes the incoming port and returns its previous state. All further attempts to Ractor.receive
in the ractor, and send
to the ractor will fail with Ractor::ClosedError
.
r = Ractor.new {sleep(500)} r.close_incoming #=> false r.close_incoming #=> true r.send('test') # Ractor::ClosedError (The incoming-port is already closed)
Closes the outgoing port and returns its previous state. All further attempts to Ractor.yield
in the ractor, and take
from the ractor will fail with Ractor::ClosedError
.
r = Ractor.new {sleep(500)} r.close_outgoing #=> false r.close_outgoing #=> true r.take # Ractor::ClosedError (The outgoing-port is already closed)
Make obj
shareable between ractors.
obj
and all the objects it refers to will be frozen, unless they are already shareable.
If copy
keyword is true
, the method will copy objects before freezing them This is safer option but it can take be slower.
Note that the specification and implementation of this method are not mature and may be changed in the future.
obj = ['test'] Ractor.shareable?(obj) #=> false Ractor.make_shareable(obj) #=> ["test"] Ractor.shareable?(obj) #=> true obj.frozen? #=> true obj[0].frozen? #=> true # Copy vs non-copy versions: obj1 = ['test'] obj1s = Ractor.make_shareable(obj1) obj1.frozen? #=> true obj1s.object_id == obj1.object_id #=> true obj2 = ['test'] obj2s = Ractor.make_shareable(obj2, copy: true) obj2.frozen? #=> false obj2s.frozen? #=> true obj2s.object_id == obj2.object_id #=> false obj2s[0].object_id == obj2[0].object_id #=> false
See also the “Shareable and unshareable objects” section in the Ractor
class docs.
Returns an arbitrary seed value. This is used by Random.new
when no seed value is specified as an argument.
Random.new_seed #=> 115032730400174366788466674494640623225
Returns an array of the names of the thread-local variables (as Symbols).
thr = Thread.new do Thread.current.thread_variable_set(:cat, 'meow') Thread.current.thread_variable_set("dog", 'woof') end thr.join #=> #<Thread:0x401b3f10 dead> thr.thread_variables #=> [:dog, :cat]
Note that these are not fiber local variables. Please see Thread#[]
and Thread#thread_variable_get
for more details.
Returns true
if the given string (or symbol) exists as a thread-local variable.
me = Thread.current me.thread_variable_set(:oliver, "a") me.thread_variable?(:oliver) #=> true me.thread_variable?(:stanley) #=> false
Note that these are not fiber local variables. Please see Thread#[]
and Thread#thread_variable_get
for more details.
Returns the number of threads waiting on the queue.
Returns the number of threads waiting on the queue.
Compiled source code (String
) on *eval methods on the :script_compiled
event. If loaded from a file, it will return nil.
Returns an array of the names of global variables. This includes special regexp global variables such as $~
and $+
, but does not include the numbered regexp global variables ($1
, $2
, etc.).
global_variables.grep /std/ #=> [:$stdin, :$stdout, :$stderr]
Controls tracing of assignments to global variables. The parameter symbol
identifies the variable (as either a string name or a symbol identifier). cmd (which may be a string or a Proc
object) or block is executed whenever the variable is assigned. The block or Proc
object receives the variable’s new value as a parameter. Also see Kernel::untrace_var.
trace_var :$_, proc {|v| puts "$_ is now '#{v}'" } $_ = "hello" $_ = ' there'
produces:
$_ is now 'hello' $_ is now ' there'
Removes tracing for the specified command on the given global variable and returns nil
. If no command is specified, removes all tracing for that variable and returns an array containing the commands actually removed.
Yields self to the block and returns the result of the block.
"my string".yield_self {|s| s.upcase } #=> "MY STRING"
Good usage for then
is value piping in method chains:
require 'open-uri' require 'json' construct_url(arguments). then {|url| open(url).read }. then {|response| JSON.parse(response) }
Ruby tries to load the library named string relative to the requiring file’s path. If the file’s path cannot be determined a LoadError
is raised. If a file is loaded true
is returned and false otherwise.
Returns the names of the current local variables.
fred = 1 for i in 1..10 # ... end local_variables #=> [:fred, :i]
Returns a new array containing the truthy results (everything except false
or nil
) of running the block
for every element in enum
.
If no block is given, an Enumerator
is returned instead.
(1..10).filter_map { |i| i * 2 if i.even? } #=> [4, 8, 12, 16, 20]
Returns a new array with the concatenated results of running block once for every element in enum.
If no block is given, an enumerator is returned instead.
[1, 2, 3, 4].flat_map { |e| [e, -e] } #=> [1, -1, 2, -2, 3, -3, 4, -4] [[1, 2], [3, 4]].flat_map { |e| e + [100] } #=> [1, 2, 100, 3, 4, 100]
Iterates the given block for each array of consecutive <n> elements. If no block is given, returns an enumerator.
e.g.:
(1..10).each_cons(3) { |a| p a } # outputs below [1, 2, 3] [2, 3, 4] [3, 4, 5] [4, 5, 6] [5, 6, 7] [6, 7, 8] [7, 8, 9] [8, 9, 10]
Drops elements up to, but not including, the first element for which the block returns nil
or false
and returns an array containing the remaining elements.
If no block is given, an enumerator is returned instead.
a = [1, 2, 3, 4, 5, 0] a.drop_while { |i| i < 3 } #=> [3, 4, 5, 0]
Creates an enumerator for each chunked elements. The ends of chunks are defined by pattern and the block.
If pattern === elt
returns true
or the block returns true
for the element, the element is end of a chunk.
The ===
and block is called from the first element to the last element of enum.
The result enumerator yields the chunked elements as an array. So each
method can be called as follows:
enum.slice_after(pattern).each { |ary| ... } enum.slice_after { |elt| bool }.each { |ary| ... }
Other methods of the Enumerator
class and Enumerable
module, such as map
, etc., are also usable.
For example, continuation lines (lines end with backslash) can be concatenated as follows:
lines = ["foo\n", "bar\\\n", "baz\n", "\n", "qux\n"] e = lines.slice_after(/(?<!\\)\n\z/) p e.to_a #=> [["foo\n"], ["bar\\\n", "baz\n"], ["\n"], ["qux\n"]] p e.map {|ll| ll[0...-1].map {|l| l.sub(/\\\n\z/, "") }.join + ll.last } #=>["foo\n", "barbaz\n", "\n", "qux\n"]
Makes a set from the enumerable object with given arguments. Needs to require "set"
to use this method.